This collection reviews current research on understanding nutrient cycles, the ways crops process nutrients, the environmental effects of fertilizer use and how this understanding can be used to improve nutrient use efficiency for a more resource-efficient and climate-smart agriculture. Parts 1-3 summarise research on the primary macronutrients: nitrogen, phosphorus and potassium. Chapters review what we know about nutrient cycles, crop nutrient processing, potential environmental effects and ways of optimising nutrient use efficiency (NUE). The fourth section of the book discusses secondary macronutrients and micronutrients including: calcium, iron, zinc, boron, manganese and molybdenum as well as soil organic matter. The final part of the book reviews research on optimising fertiliser use. Chapters cover topics such as assessing nutrient availability and advances in integrated plant nutrient management. Other chapters discuss enhanced efficiency fertilisers, the use of bio-effectors/bio-stimulants, fertigation techniques, foliar fertilizers and the use of treated wastes in crop nutrition.